Proximate composition and hyperlipidemia lowering potential of rice bran enriched with yam flour

Abstract

The proximate composition and hyperlipidemia lowering potential of rice bran enriched yam flour were evaluated. The flours were formulated at the ratios of 100:0, 95:5, 90:10, 85:15, 80:20 and 0:100 of yam flour to rice bran flour. The proximate composition, dietary fibre, and functional properties of the flours were determined. Six rat groups were fed the respective flours for three weeks. At the end, their blood lipid profiles were measured. The results showed that the protein, ash, fat and crude/dietary fibre contents of the flours were increased with increase in the percentage levels of the added rice bran flour. While the bulk density, water absorption capacity, and swelling index of the flours decreased, the oil absorption capacity, emulsion capacity, gelatinization temperature and foaming capacity increased, with increase in the percentage levels of added rice bran flour. The ranges for serum total cholesterol, total triglyceride, high density lipoprotein cholesterol and low density lipoprotein cholesterol of the rats were 82.42-122.42, 40.56-57.54, 40.09-64.14 and 10.18-70.82mg/dl, respectively. Apart from high density lipoprotein cholesterol which increased, all the other lipid profile values were reduced as the percentage level of substitution of yam flour with rice bran particles increased. The T-test showed significant relationship between the dietary fibre (rice bran) of samples 90:10, 85:15, 80:20 and 0:100 and the serum lipids of the respective rat groups. Therefore, substitution of yam flour with rice bran flour improved the nutrient profile, reduced the ‘bad’ cholesterols and raised the ‘good’ cholesterol in the blood serum of rats.

Keywords: Dietary fibre, protein, functional properties, cholesterol, triglycerides